TMP91C824
91C824-168
(5) Restart
Restart is used to change the direction of data transfer between a master device and a slave device
during transferring data. The following explains how to restart when the TMP91C824F is in the
master mode.
Clear “0” to the SBI0CR2<MST,TRX,BB>, and set “1” to the <PIN> and release the bus. The SDA
line remains the High-level and the SCL pin is released. Since a stop condition is not generated on a
bus, a bus is assumed to be in a busy state from other devices. Check the SBI0SR<BB> is “0” and
SCL terminal level is “1” to check that the TMP91C824F is released. Check the <LRB> until it
becomes “1” to check that the SCL line on a bus is not pulled down to the low-level by other devices.
After confirming that a bus stays in a free state, generate a start condition with procedure 3.10.6 (2).
In order to meet setup time when restarting, take at least 4.7
μ
s of waiting time by software from
the time of restarting to confirm that the bus is free until the time to generate the start condition.
0
→
<MST>
0
→
<TRX>
0
→
<BB>
1
→
<PIN>
1
→
<MST>
1
→
<TRX>
1
→
<BB>
1
→
<PIN>
SCL line
Internal SCL
output
(TMP91C815)
SDA line
<LRB>
4.7[
µ
s] (Min.)
Start codnition
<BB>
<PIN>
9
Figure 3.10.19 Timing diagram for TMP91C824F Restart